A few years ago this double bill would have testified to nonmainstream country’s hard-won success in Nashville, but not now: the Mavericks may still work out of Music City, but stylistically they’re a million miles away, while BR5-49, hemmed in by the neotraditionalism that got them noticed in the first place, are taking a graceless tumble down the charts. With their latest album, Trampoline (MCA), the Mavericks continue to veer further away from country orthodoxy and toward a beguiling, if occasionally kitschy, eclecticism. The album’s been on the country charts since its release early this year–a tribute to the band’s intrinsic musicality–but it’s still a freak show. Drenched with ripe horns and lush strings, Raul Malo’s new songs leap all over the map–from hard soul (“Tell Me Why”) to early Beatles pop (“To Be With You”) to gospel (“Save a Prayer”) to Roy Orbison grandeur (“Dream River”) to Vegas-era Elvis (“I’ve Got This Feeling”) to jangle pop (“I Don’t Even Know Your Name”) to instrumental exotica (“Melbourne Mambo”). But, amazingly, all the bumps are smoothed by Malo’s liquid croon, with its shimmery tremolos, sophisticated dips, and elegant glides–a voice more informed by lounge singing than country warbling. It would’ve been nice if the Mavericks had tossed in some of the earnest countrypolitan that makes 1994’s What a Crying Shame their best album–and no doubt we’ll get some of that at this show–but they seem to be having too much fun playing by their own rules. Big Backyard Beat Show (Arista), BR5-49’s follow-up to their surprisingly successful debut, piles on more of the quintet’s succinct retro machinations, but the songwriting just isn’t up to snuff. The band has always mixed its own songs with an encyclopedic range of classic covers, but its treatments of Buck Owens’s “There Goes My Love” and Billy Joe Shaver’s “Georgia on a Fast Train” outshine all nine of the new originals. The inclusion of the band’s “18 Wheels and a Crowbar,” which appeared previously on the live EP Live From Robert’s, also suggests that BR5-49’s pool may be shallower than it looks. Still, the band is a hoot live. Sunday, 7:30 PM, Skyline Stage, Navy Pier, 600 E. Grand; 312-595-7437 or 312-559-1212. PETER MARGASAK

Art accompanying story in printed newspaper (not available in this archive): Mavericks photo by Jim McGuire.